This description relates to interconnection devices, and more particularly to interconnection devices which connect an array of contacts within a digital or analog transmission system.
High speed communication between two printed circuit cards over an interconnection device with a dense array of contacts may result in cross-talk between communication channels within the interconnection device and a resulting degradation of signal integrity. In addition to cross-talk between communication channels, high speed communication across an interconnection device may generate undesirable levels of noise. Reduction of cross-talk and noise while at the same time maintaining a dense array of contacts within an interconnection device is often a design goal.
In an aspect, the invention features an intercoupling component for receiving an array of contacts within a digital or analog transmission system having an electrical ground circuit and a chassis ground circuit. A plurality of electrically conductive contacts are disposed within holes formed on a segment formed of insulative material. One or more electrically conductive shields are disposed within the segment and are configured to connect to the chassis ground circuit of the system.
Embodiments may include one or more of the following. At least some of the plurality of the electrically conductive contacts disposed within the holes on the segment may be configured to electrically connect with the electrical ground circuit of the system.
A frame formed of electrically conductive material may surround the segment and be in electrical contact with both the shield member and the electrical ground circuit of the system. The frame may be molded around the segments.
One or more ground planes which are configured to electrically connect with the electrical ground circuit of the system may be disposed within the segment. One or more cavities filled with air may be disposed on the segment.
The intercoupling component may further include a retention member configured to releasably retain an array mating of contacts with the plurality of electrically conductive contacts.
In another aspect, the invention features an intercoupling component for receiving an array of contacts within a digital or analog transmission system having an electrical ground circuit and a chassis ground circuit. A plurality of electrically conductive contacts are disposed within holes formed on a plurality of segments, each formed of insulative material. One or more electrically conductive shields are disposed within gaps between adjacent segments and are connected to the chassis ground circuit of the system.
In another aspect, the invention features an intercoupling component for receiving an array of contacts within a digital or analog transmission system having one or more segments formed of electrically insulative material and having an upper and lower surface, the segment including a plurality of holes disposed on its upper surface and arranged in a predetermined footprint corresponding to the array of a contacts and a plurality of electrically conductive contacts each disposed within each hole on the upper surface of the segment. The plurality of contacts are arranged in a plurality of multi-contact groupings, with at least one multi-contact grouping including a first electrically conductive contact and a reference contact. The reference contact is located at a distance D from the first electrically conductive contact and is configured to electrically connect to the electrical ground circuit of the system.
Embodiments may include one or more of the following. The first electrically conductive contact and reference may be configured to form a transmission line electrically equivalent to a co-axial transmission line. The first electrically conductive contact may be configured to transmit single-ended signals. Additionally, each multi-contact grouping may be located a distance of xe2x89xa7D from adjacent multi-contact groupings.
The intercoupling component may also include a second electrically conductive contact member located at a distance D2 from the first electrically conductive contact. The first and second electrically conductive contacts may form a transmission line electrically equivalent to a twin-axial differential transmission line. The first and second electrically conductive contacts within each multi-contact grouping may be configured to transmit disparate single-ended signals or low-voltage differential signals. Additionally, each multi-contact grouping may be located a distance xe2x89xa7D2 from adjacent multi-contact groupings.
The first and second electrically conductive contacts may have substantially the same cross-section, initial characteristic impedance, capacitance, and inductance.
The intercoupling component may also include one or more shield members formed of electrically conductive material disposed within the segment and configured to connect to the chassis ground circuit of the system. Additionally, the intercoupling component may include a frame disposed around the one or more segments.
In another aspect of the invention, a circuit card for use in a digital or analog transmission system having an electrical ground circuit and a chassis ground circuit, the circuit card includes a printed circuit board having a plurality of contact pads arranged in a predetermined footprint; and an interconnection device. The interconnection device includes one or more segments having an upper and lower surface, the upper surface of the segment having a plurality of holes arranged in a predetermined footprint to match the predetermined footprint of the plurality of surface mount pads, a plurality of electrically conductive contact member disposed within each of the holes and electrically connected to their respective surface mount pad, and one or more a shield members formed of electrically conductive material disposed within the segment. Additionally, a frame formed of electrically conductive material surrounds the one or more segments and the frame is electrically connected the shield member and to the chassis ground circuit of the system.
Additional embodiments include one or more of the following features. The plurality of contacts may be arranged in a plurality of multi-contact groupings which includes a first electrically conductive contact; and a reference contact located at a distance D from the first electrically conductive contact and connected to the electrical ground circuit of the system.
The plurality of multi-contact groupings may also include a second electrically conductive contact located a distance D2 from the first electrically conductive contact.
The first and second electrically conductive contacts have substantially the same cross-section, capacitance and inductance. The first and second electrically conductive contacts may be configured to transmit low voltage differential signals or disparate single ended signals.
In another aspect of the invention, an intercoupling component for receiving an array of contacts within a digital or analog transmission system having an electrical ground circuit, the intercoupling component includes a segment formed of a material having a dielectric constant Er1. The segment has an upper and lower surface and a plurality of holes are disposed on the upper surface of the segment. A first signal contact disposed within a first hole on the segment and a second signal contact disposed within a second hole on the segment adjacent to the first hole in which the first signal contact is disposed. The segment also includes a cavity formed between the first and second signal contacts.
Additional embodiments include one or more of the following features. The cavity may be formed on the upper surface, lower surface or within the segment and may be is open to air. An insert formed of a material having a dielectric constant of Er1 may be disposed within the cavity.
The intercoupling component may include a plurality of first signal contacts disposed within a plurality of holes and a plurality of second signal contacts each disposed within a hole that is adjacent to a hole containing a first signal contact. The segment may include a cavity disposed between each pair of first and second signal contacts. The intercoupling component may also include ground contacts disposed within holes on the segment or a ground plane.
In another aspect of the invention, a method for adjusting the differential impedance of a pair of differential transmission lines in a interconnection device for receiving an array of contacts within a digital or analog transmission system having an electrical ground circuit, the intercoupling component. The method includes providing a segment having a dielectric constant Er1 and having an upper and lower surface and including a plurality of holes disposed on its upper surface. Providing a pair of signal contacts disposed within two adjacent holes on the segment, the pair of signal contacts configured to transmit differential signals. Spacing the pair of signal contacts such that they create a certain differential impedance of the two contacts in the pair of signal contacts. Providing a cavity in the segment between the two signal contacts in the pair of signal contacts to adjust the differential impedance between the pair of signal contacts.
Additional embodiments include one or more of the following steps. Inserting a material having a dielectric constant of Er2 in the cavity in the segment.
Providing a plurality of pairs of signal contacts disposed with a plurality of adjacent holes on the segment, the plurality of pairs of signal contacts forming an array of pairs of signal contacts disposed in the segment. Providing a plurality of cavities disposed in the segment between the two signal contacts in each pair of signal contacts to adjust the differential impedance of the two signal contacts in each pair of signal contacts.
Providing a plurality of ground contacts disposed within a plurality of holes on the segment and within the array of pairs of signal contacts, the plurality of ground contacts electrically connected to the electrical ground circuit of the system.
Providing a ground plane disposed within the segment and within the array of pairs of signal contacts, the ground plane configured to electrically connect with the electrical ground of the system.
Embodiments of the invention may have one or more of the following advantages.
One or more contacts disposed within the array of contacts and are configured to connect to the electrical ground of the system may help to reduce cross-talk between two or more contacts during signal transmission. Additionally, the use of a electrically conductive shield member connected to the chassis ground of the system and disposed within or between one or more segments may help to reduce undesired electromagnetic fields generated by high-speed electron flow over the contact array during operation.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.